In an image forming apparatus such as machine multi-function peripheral (MFP), a discharge speed of a sheet increases as a result of increased scanning speed. Thus, after discharging, the sheets may be uneven or dropped onto a floor without being contained in the sheet discharge tray. Therefore, when a large amount of documents are scanned, a user must take time to align the sheets. In addition, when one or more sheets drop, it may be difficult to return the sheets to an original page order. There is also a case where sometimes a part of the sheet is lost because a user did not notice the drop.
In order to prevent the sheet discharged after scanning from dropping, a shape of a sheet discharge tray may be altered. However, although it is possible to suppress dropping of the sheet, the problem related to dropping of the sheet after the scanning cannot be satisfactorily solved.